1/*
2 *	Implements the IPX routing routines.
3 *	Code moved from af_ipx.c.
4 *
5 *	Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 2003
6 *
7 *	See net/ipx/ChangeLog.
8 */
9
10#include <linux/list.h>
11#include <linux/route.h>
12#include <linux/slab.h>
13#include <linux/spinlock.h>
14
15#include <net/ipx.h>
16#include <net/sock.h>
17
18LIST_HEAD(ipx_routes);
19DEFINE_RWLOCK(ipx_routes_lock);
20
21extern struct ipx_interface *ipx_internal_net;
22
23extern __be16 ipx_cksum(struct ipxhdr *packet, int length);
24extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
25extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
26			       struct sk_buff *skb, int copy);
27extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
28			       struct sk_buff *skb, int copy);
29extern int ipxitf_send(struct ipx_interface *intrfc, struct sk_buff *skb,
30		       char *node);
31extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
32
33struct ipx_route *ipxrtr_lookup(__be32 net)
34{
35	struct ipx_route *r;
36
37	read_lock_bh(&ipx_routes_lock);
38	list_for_each_entry(r, &ipx_routes, node)
39		if (r->ir_net == net) {
40			ipxrtr_hold(r);
41			goto unlock;
42		}
43	r = NULL;
44unlock:
45	read_unlock_bh(&ipx_routes_lock);
46	return r;
47}
48
49/*
50 * Caller must hold a reference to intrfc
51 */
52int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
53		     unsigned char *node)
54{
55	struct ipx_route *rt;
56	int rc;
57
58	/* Get a route structure; either existing or create */
59	rt = ipxrtr_lookup(network);
60	if (!rt) {
61		rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
62		rc = -EAGAIN;
63		if (!rt)
64			goto out;
65
66		atomic_set(&rt->refcnt, 1);
67		ipxrtr_hold(rt);
68		write_lock_bh(&ipx_routes_lock);
69		list_add(&rt->node, &ipx_routes);
70		write_unlock_bh(&ipx_routes_lock);
71	} else {
72		rc = -EEXIST;
73		if (intrfc == ipx_internal_net)
74			goto out_put;
75	}
76
77	rt->ir_net 	= network;
78	rt->ir_intrfc 	= intrfc;
79	if (!node) {
80		memset(rt->ir_router_node, '\0', IPX_NODE_LEN);
81		rt->ir_routed = 0;
82	} else {
83		memcpy(rt->ir_router_node, node, IPX_NODE_LEN);
84		rt->ir_routed = 1;
85	}
86
87	rc = 0;
88out_put:
89	ipxrtr_put(rt);
90out:
91	return rc;
92}
93
94void ipxrtr_del_routes(struct ipx_interface *intrfc)
95{
96	struct ipx_route *r, *tmp;
97
98	write_lock_bh(&ipx_routes_lock);
99	list_for_each_entry_safe(r, tmp, &ipx_routes, node)
100		if (r->ir_intrfc == intrfc) {
101			list_del(&r->node);
102			ipxrtr_put(r);
103		}
104	write_unlock_bh(&ipx_routes_lock);
105}
106
107static int ipxrtr_create(struct ipx_route_definition *rd)
108{
109	struct ipx_interface *intrfc;
110	int rc = -ENETUNREACH;
111
112	/* Find the appropriate interface */
113	intrfc = ipxitf_find_using_net(rd->ipx_router_network);
114	if (!intrfc)
115		goto out;
116	rc = ipxrtr_add_route(rd->ipx_network, intrfc, rd->ipx_router_node);
117	ipxitf_put(intrfc);
118out:
119	return rc;
120}
121
122static int ipxrtr_delete(__be32 net)
123{
124	struct ipx_route *r, *tmp;
125	int rc;
126
127	write_lock_bh(&ipx_routes_lock);
128	list_for_each_entry_safe(r, tmp, &ipx_routes, node)
129		if (r->ir_net == net) {
130			/* Directly connected; can't lose route */
131			rc = -EPERM;
132			if (!r->ir_routed)
133				goto out;
134			list_del(&r->node);
135			ipxrtr_put(r);
136			rc = 0;
137			goto out;
138		}
139	rc = -ENOENT;
140out:
141	write_unlock_bh(&ipx_routes_lock);
142	return rc;
143}
144
145/*
146 * The skb has to be unshared, we'll end up calling ipxitf_send, that'll
147 * modify the packet
148 */
149int ipxrtr_route_skb(struct sk_buff *skb)
150{
151	struct ipxhdr *ipx = ipx_hdr(skb);
152	struct ipx_route *r = ipxrtr_lookup(IPX_SKB_CB(skb)->ipx_dest_net);
153
154	if (!r) {	/* no known route */
155		kfree_skb(skb);
156		return 0;
157	}
158
159	ipxitf_hold(r->ir_intrfc);
160	ipxitf_send(r->ir_intrfc, skb, r->ir_routed ?
161			r->ir_router_node : ipx->ipx_dest.node);
162	ipxitf_put(r->ir_intrfc);
163	ipxrtr_put(r);
164
165	return 0;
166}
167
168/*
169 * Route an outgoing frame from a socket.
170 */
171int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
172			struct iovec *iov, size_t len, int noblock)
173{
174	struct sk_buff *skb;
175	struct ipx_sock *ipxs = ipx_sk(sk);
176	struct ipx_interface *intrfc;
177	struct ipxhdr *ipx;
178	size_t size;
179	int ipx_offset;
180	struct ipx_route *rt = NULL;
181	int rc;
182
183	/* Find the appropriate interface on which to send packet */
184	if (!usipx->sipx_network && ipx_primary_net) {
185		usipx->sipx_network = ipx_primary_net->if_netnum;
186		intrfc = ipx_primary_net;
187	} else {
188		rt = ipxrtr_lookup(usipx->sipx_network);
189		rc = -ENETUNREACH;
190		if (!rt)
191			goto out;
192		intrfc = rt->ir_intrfc;
193	}
194
195	ipxitf_hold(intrfc);
196	ipx_offset = intrfc->if_ipx_offset;
197	size = sizeof(struct ipxhdr) + len + ipx_offset;
198
199	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
200	if (!skb)
201		goto out_put;
202
203	skb_reserve(skb, ipx_offset);
204	skb->sk = sk;
205
206	/* Fill in IPX header */
207	skb_reset_network_header(skb);
208	skb_reset_transport_header(skb);
209	skb_put(skb, sizeof(struct ipxhdr));
210	ipx = ipx_hdr(skb);
211	ipx->ipx_pktsize = htons(len + sizeof(struct ipxhdr));
212	IPX_SKB_CB(skb)->ipx_tctrl = 0;
213	ipx->ipx_type 	 = usipx->sipx_type;
214
215	IPX_SKB_CB(skb)->last_hop.index = -1;
216#ifdef CONFIG_IPX_INTERN
217	IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
218	memcpy(ipx->ipx_source.node, ipxs->node, IPX_NODE_LEN);
219#else
220	rc = ntohs(ipxs->port);
221	if (rc == 0x453 || rc == 0x452) {
222		/* RIP/SAP special handling for mars_nwe */
223		IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;
224		memcpy(ipx->ipx_source.node, intrfc->if_node, IPX_NODE_LEN);
225	} else {
226		IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
227		memcpy(ipx->ipx_source.node, ipxs->intrfc->if_node,
228			IPX_NODE_LEN);
229	}
230#endif	/* CONFIG_IPX_INTERN */
231	ipx->ipx_source.sock		= ipxs->port;
232	IPX_SKB_CB(skb)->ipx_dest_net	= usipx->sipx_network;
233	memcpy(ipx->ipx_dest.node, usipx->sipx_node, IPX_NODE_LEN);
234	ipx->ipx_dest.sock		= usipx->sipx_port;
235
236	rc = memcpy_fromiovec(skb_put(skb, len), iov, len);
237	if (rc) {
238		kfree_skb(skb);
239		goto out_put;
240	}
241
242	/* Apply checksum. Not allowed on 802.3 links. */
243	if (sk->sk_no_check || intrfc->if_dlink_type == htons(IPX_FRAME_8023))
244		ipx->ipx_checksum = htons(0xFFFF);
245	else
246		ipx->ipx_checksum = ipx_cksum(ipx, len + sizeof(struct ipxhdr));
247
248	rc = ipxitf_send(intrfc, skb, (rt && rt->ir_routed) ?
249			 rt->ir_router_node : ipx->ipx_dest.node);
250out_put:
251	ipxitf_put(intrfc);
252	if (rt)
253		ipxrtr_put(rt);
254out:
255	return rc;
256}
257
258/*
259 * We use a normal struct rtentry for route handling
260 */
261int ipxrtr_ioctl(unsigned int cmd, void __user *arg)
262{
263	struct rtentry rt;	/* Use these to behave like 'other' stacks */
264	struct sockaddr_ipx *sg, *st;
265	int rc = -EFAULT;
266
267	if (copy_from_user(&rt, arg, sizeof(rt)))
268		goto out;
269
270	sg = (struct sockaddr_ipx *)&rt.rt_gateway;
271	st = (struct sockaddr_ipx *)&rt.rt_dst;
272
273	rc = -EINVAL;
274	if (!(rt.rt_flags & RTF_GATEWAY) || /* Direct routes are fixed */
275	    sg->sipx_family != AF_IPX ||
276	    st->sipx_family != AF_IPX)
277		goto out;
278
279	switch (cmd) {
280	case SIOCDELRT:
281		rc = ipxrtr_delete(st->sipx_network);
282		break;
283	case SIOCADDRT: {
284		struct ipx_route_definition f;
285		f.ipx_network		= st->sipx_network;
286		f.ipx_router_network	= sg->sipx_network;
287		memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
288		rc = ipxrtr_create(&f);
289		break;
290	}
291	}
292
293out:
294	return rc;
295}
296